In addition to delivering playback sound, such as music or other audio signals, to a user, some headphones may also control the ambient sound in the vicinity of the user that is heard by the user. For example, some headphones may include active noise cancellation (ANC) in order to permit a user to better hear the playback sound delivered via the headphones in a relatively noisy environment or to otherwise block at least some of the background noise that may otherwise be distracting to the user. Some headphones that include ANC may permit the level of ANC to be controlled such that the level of ambient noise heard by the user can be controlled.
Headsets that include ANC generally attenuate the ambient noise both by mechanical attenuation, such as provided by in-ear headphones or headphones that have a similar type of structure to ear protectors, and by noise cancellation signal processing. The noise cancellation signaling processing may be performed by the headset or by a separate device, such as a dongle, connected to the headset. A headset that includes ANC may include a switch or other input that permits the ANC to be turned on and off by the user.
Another technique to control the level of ambient sound heard by the user of a headset is to employ acoustic transparency. In this regard, a headset that naturally attenuates the ambient sound in a mechanical fashion, such as provided by an in-ear headset, may also provide acoustic transparency to enable for example, augmented reality audio. In order to provide acoustic transparency, a virtual sound source is added to the real audio environment of a user, such as the ambient sound that would be heard by the user if the user were not wearing headphones.
Some headsets may combine both acoustic transparency and ANC functionality to enable a transition from complete acoustic transparency to complete ANC with various hybrid combinations of acoustic transparency and ANC therebetween. By combining acoustic transparency and ANC functionality, the continuum of the volume of the user's sound environment may transition from total blocking of the acoustic environment to total transparency.
Some headsets that include ANC functionality also include an acoustic hear-through functionality. The acoustic hear-through functionality can be actuated with a separate control input and, once actuated, permits the user to have a conversation. In this regard, the user may have a conversation since audio signals having speech frequencies are not cancelled once the acoustic hear-through functionality has been actuated even though the ANC functionality generally remains operational, at least for audio signals having frequencies other than the speech frequencies.
In addition to providing an input to activate or deactivate the ANC functionality and/or acoustic transparency, the user may separately control the volume of the playback sound. As a result of the multiple controls that may be configured or set by the user, the user may be confused or otherwise unable to determine the preferred setting for the volume of the playback sound and the ambience level of the ambient sound. As such, some users of headphones may simply always leave the ANC functionality or the acoustic transparency activated and may then separately control the volume of the playback sound, such as by increasing volume of the playback sound in instances in which the ambient sound is louder and by reducing the volume of the playback sound in instances in which the ambient sound is softer. In particularly noisy environments, the user may simply increase the volume of the playback sound and, in some instances, may increase the volume of the playback sound to such a level that the combined volume of the playback sound and the ambience level of the ambient sound is uncomfortable for the user.